Among various display devices, a liquid crystal display device, for example, drives liquid crystal by applying thereto an electric field generated between a pixel electrode and a common electrode (also referred to as a counter electrode), which are formed in each pixel region, to adjust an amount of light transmitted through a region between the pixel electrode and the common electrode, thereby displaying an image. A common voltage (Vcom) is supplied to the common electrode from an external circuit through a common bus line. Conventionally, there has been proposed a configuration in which, in the liquid crystal display device in a prior art, a plurality of common wirings is provided in a display region in order to stably supply the common voltage to the common electrode (for example, see Japanese Unexamined Patent Application Publication 2005-157404).
In the liquid crystal display device disclosed in the prior art, a common bus line is provided on one side surface of a display panel, and a plurality of common wirings (counter voltage signal lines) extending in the direction same as the direction in which a gate line extends is connected to the common bus line. The common voltage supplied to the common bus line from the external circuit is then supplied to the common electrodes through the common wirings.
However, the conventional liquid crystal display device has a problem such that efficiency of supplying the common voltage to the common electrodes is low due to the influence of resistance of the common bus line. The low efficiency of supplying the common voltage entails deterioration of display quality.